Treatment of cellulosic material



fibrous matter.

Patented Apr. 7, 1942 TREATMENT OF CELLULO SIC MATERIAL Alfred William Baldwin, John Gwynant Evans, and Charles Edward Salkeld, Blackley, Manchester, England, assignors to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Original application December 1,

1936, Serial No.'113,702. Divided and this application June 13,1941, Serial No. 397,906. In Great Britain June 8, 1936 8 Claims.

This invention relates to a treatment of cellulosic materials, whereby they are given a permanent finish and other improved properties, the

- instant application being a division of our copending application 1 Serial No. 113,702, filed December 1, 1936.

We use the term cellulosic materials to include cotton and other cellulosic natural, fibres and regenerated cellulose substances in the form of fibre or film. Cellulosic natural fibres include 1 flax, jute, hemp, and sisal, wood pulp and other seed coat or bast or other vegetable structural These andcotton are used in the manufacture of yarn and knitted and woven fabrics, and for making paper and cardboard.

The invention is applicable to the treatment of fibres in any stage of their-manufacture. It is, however, particularly directed to the manufacture of woven materials with improved properties. When woven material or spun yarn is in question, the invention is-not limited to the treatment of fabrics or yarns composed wholly of the cellulosic material, but includes also a treatment'of composite fabrics or yarns, for instance, of union fabrics.

The improved properties conferred on, the cellulose materials after they have been treated according to the invention may be collectively described as permanent water-repellent properties. -In particular, woven fabrics may be so treated as to become water-repellent or showerproof, and. this finish is permanent, that is, it is unaffected or not seriously affected by exposure to the weather, or by laundering, drycleaning, or other cleansing operations. Moreover, the handle of the treatedmaterials' (i. e.

fication, when necessary, of the mode of treatment according to this invention, fabrics and yarns of varied soft handle may be obtained. This softening effect is likewise, of course, permanent. v

The process of this invention is applicable to cellulosic materials-whether or not they have been dyed. When, however, the materials have been dyed with certain dyestuffs substantive towards cellulose, namely, those of the direct cotton colour group. then another effect of the treatment is that the dyestuffs become more permanently attached to the material, 1. e. dyestuffs of this group become fixed.

According to the invention we impregnate the said cellulosic materials with a quaternary ammonium compound of the general formula I R-N-.-CHz-N(tert)-X I RI! as more fully defined below, which is applied from aqueous medium, and we then heat the so-im- 'pregnated material to the decomposition temperature of said compound, preferably after previous drying.

In the above general Formula LR stand for radicals at least one of which consists of "or contains an aliphatic hydrocarbon radical of 10 or more carbon atoms which may be normal or branched paraffinoid or ethylenoid or may be a more complicated aliphatic hydrocarbon structure as in the parent hydrocarbon of the naphthenic acids or their hydrogenation products. Thus, the group B" may be of the'form R-C O-N- where R-CO- is the radical of a fatty acid,i. e.

\ yarns and fabrics) is soft. By appropriate modi- .the radical of the acid of a fat or fatty oil, or the radical of a physically similar acid, and R," then is hydrogen or a hydrocarbon radical; or the group R-lTI-- V RI! may be of the form and then R is the aliphatic hydrocarbon radical stands for a tertiary amine which is either,

heterocyclic or aliphatic.

When N (tert) is heterocyelic it is typified by pyridine, but picoline or other pyridineand R" ed to the bath.

alkyl-piperidine or N-benzyl-piperidine or 0- homologues thereof; when -N-(tert) is aliphatic it is typified by trimethylamine, but triethylamine, tributylamine, triethanolamine or a dialkylcyclohexylamine will also serve. I

Finally in the formula given above X for a monovalent acid group.

In carrying the invention into practical effect the compound of Formula I above is dissolved or suspended in aqueous medium usually water alone to give a dilute aqueous solution or suspension. In general, the operation of impregnating the cellulosic material may be carried out preferably at a temperature below 40 C. especially when diluteaqueous solutions (e. g. 0.1%) are used; with more concentrated solutions (e. g. 1%) a. hotter, even boiling solution may be applied; However, when kept at temperatures above 40 C.

the solution may become acid; then a less satisstands of drying is a less important factor than and other conditions of drying. Thus, for instance, a cotton fabric impregnated with an aqueous solution of stearamidomethylpyridinium chloride and dried inmore or less stagnant air, as in an oven without artificial circulation, should preferably be not submitted to a drying temperature of more than '30 C. inasmuch as the higher the temperature at'this stage the more the intensity of the ultimate water repellent effect tends tovdiminish. When, on the other hand, the impregnated-material is dried in a brisk current of hot air so that the water is removed rapidly -(in about 3 minutes) then the factory finish, not so resistant to organic solvents,

known in the trade as limbric, a dilute aqueous 5 solution of the compound e. g. stearamidomethyl-pyridinium chloride, may be employed, and

the concentration may be as low as 0.05%. The fabric is padded in this solution, and squeezed. It then contains about its own weight of solution, and thus the amount ofcompound with which the fabric is impregnated is about the same percentage of the weight of the cloth as the percentage strength of the solution. The padding is conveniently carried out at about 40 C. Higher temperatures are preferably avoided, as the compound used tends to decompose in hot aqueous solution. Thus, a 0.5% aqueous solution of stearamidomethyl-pyridinium chloride becomes useless if it has been kept at 60 C. for

more than two hours or at 80 C. for more than one hour.

drying, temperature may rise to 80 C. without disadvantage.

Again, if the wet material impregnated in a 1% aqueous solution is dried on a steam-heated cylinder at 120 C. for e. g. one minute, no

water-repellent effect is obtained. on oontinuing the heatihgfor five minutes, water-repellent properties are indeed conferred on the material, but the so-treated material is sensitive to the actionof solvents.

The baking treatment is essential for the production of permanent water-repellent proper ties. The impregnated material begins to show water-repellent properties after baking for ten minutesat 65v but the optimum effects are obtained when baking is carried out at 90 to 120 C. Poorer results are obtained at a higher temperature, e. g. 150 C. The time of baking necessary to produce the desired finishes varies with the baking temperature and dependsalso on the nature of the impregnation reagent. The time of baking can be shortened at higher temperatures. For example using stearamidomethylpyridinium chloride one must bake at 105 C. for five minutes, or at 120 C. for one-and-a-half minutes. The baking time should, of course, be

kept at minimum to avoid damage to the fabric If desired, however, other adiuvants, such as wetting agents, or buffering agents, may be add- Suitable wetting agents are the formaldehyde-naphthalene-sulphonic acid condensation products. Alkaline substance or especially substances that have a buffering action,

may conveniently be added to assist in keeping the solutions or suspensions neutral or at least not acid to avoid tendering of the cellulosic material.

Suitable such substances are pyridine, borax, disodium hydrogen phosphate or sodium acetate. Hexamethylene-tetramine also is a suitable adiuvant as it decomposes when heated to give ammonia.

The cellulosimmaterial is passed through or dipped in this dilute aqueous bath, the mechanical handling being of course suited to the nature of the material. v

After immersion in the aqueous solution the material is preferably but not necessarily dried. If a concentrated solution even 05%. 1 used, it is not necessary to dry. The production of the desired effects is dependent to some extent on the conditions of drying and heating. Drying is preferably carried out at a relatively low temperature (hereinafter referred to as the drying temperature). The heating is at a higher temperature (conveniently called the baking tem-' perature) V The drying temperature is preferably low. It is kept low in order that there may be no premature decomposition of the salt. But temperature (tendering). 0

During the baking treatment there isdecomposition of the salt, which is made manifest when a pyridinium compound is used, by there being generated an odour of pyridine.

The following examples illustrate but do not limit the invention. The parts are by weight.

Example 1 Cotton sheeting is immersed for ten minutes at 20 C. in an impregnating bath consisting of a solution of five parts of stearamidomethylpyridinium chloride in 1000 parts of water.

The impregnated material is then squeezed and dried by heating for ten minutes at 105 C. A fabric having a water-repellent finish and soft handle is obtained. The finish is resistant to dry-cleaning and laundering.

Example 2 100 parts of cotton material which been idinium chloride. The impregnated, dy material is squeezed-dried at 40 C. and then heated for ten minutes at to- C. The

material is water-repellent and has a soft handle.

' out departing The fastness to washing of the dyeing is much improved.

In a manner similar to the above examples other compounds following the generic formula. above indicated may be used for the purposes of this invention. Among the numerous compounds actually tried by us the following may be mentioned:

Stearamidomethylpyridinium m nitrobenzenesulphonate Stearamidomethylpyridinium nitrate In place of the fatty acids thus referred to, others may be used. Thus, the starting out materials may be the fatty acids' of palm oil, cotton seed oil, tallow, or derived acids such as those obtained by the processes of fat hydrogenation.

Similarly in place of undecylamine other amines may be used, in which the starting out materials are the so-called fatty alcohols, being those made by the reduction of the aforesaid fatty acids, or obtained from natural sources, such as by saponification of spermaceti or sperm oil.

Some of the said compounds are made by bringing together a hydroxymethylamide of a fatty acid and a tertiary amine salt or an addition compound of a tertiary amine and an inorganic acid anhydride: for example, stearohydroxymethylamide (made from stearamide and paraformaldehyde) is treated with pyridine hydrochloride in pyridine; or stearamide, paraformaldehyde, and anhydrous pyridine hydrochloride,

pyridine-nitrate, pyridine m nitrobenzene-sulfonate or the like are caused to react together in pyridine solution; or stearomethylamide, formaldehyde and hydrogen chloride are interact to give stearomethylamido methyl chloride, which is then combined with pyridine or other tertiary amine (methyl heptadecylcarbam ate behaves similarly to stearomethylamide) Instead of pyridine in the last mentioned synthesis trimethylamine or triethanolamine may be used.

Methods of making some of the compounds the use of which is contemplated in the invention are the subject of U. S. Patents 2,131,362, 2,147,811 and 2,146,392, which were at one time copending with our parent application above referred to.

It will be'understood that the above examples caused to v are merely illustrative, and that the details of procedure may from the spirit of this invention. For instance, the temperature of the baking treatment may vary from 70 to 200 C., the duration of the treatment being conveniently adjusted so as to avoid undue injury to the fibre.

In practice the time of the baking-treatment may vary from a few seconds to one hour.

Likewise the drying treatment may vary as to time and temperature as already indicated above. 1

The concentration of the treating agent in the aqueous solution may vary from 0.01% to 2% or even higher if desired. The quantity of the agent applied with respect to the weight of fibre treated may be so chosen by controlling the amount of solution left upon the fibre after the bulk of the be varied within wide limits, withliquid has been squeezed out and may be from 0.01 %to 2% or more by weight of the fibre.

Many other variations and modifications will be apparent to those skilled in this art.

In the claims below, the phrase long-chain as applied to an aliphatic compound or radical is meant to specify that the compound or radical contains not less than 10 carbon atoms.

We claim:

1. The process oftreating cellulosic material whereby to impart thereto water-repellent properties which comprises heating the same ata temperature between '70 and 200 C., in the abs'ence of moisture, butin intimate contact with a quaternary organic nitrogen compound formed by the interaction between a tertiary organic nitrogeneous base selected from the group consisting of heterocyclic and aliphatic tertiary bases on the one hand and a long chain aliphatic carbamate of.the general formula on the other hand, wherein R stands for the I hydrocarbon radical of an alcohol'adapted to esterify a COOH group, ,R" stands for an aliphatic hydrocarbon radical having at least 10 carbon atoms, while X is the anion of a salt forming acid.

2. The process of treating cellulosic textile ma.- terial whereby to impart thereto water repellent characteristics, which "comprises impregnatin the same with an aqueous solution ofan N-carboalkoxy alkylamino methylene pyridinium salt, wherein the alkyl radical which is attached didirectly to the nitrogen atom contains not less than 10 carbon atoms, drying the impregnated material at a temperature insufiicient to decompose saidpyridinium compound and then heating the dried material at a temperature suflicient to decompose said'pyridinium compound'a evidenced by the liberation of free pyridine.

3. The process of treating cellulosic material whereby to impart thereto improved surface characteristics which comprise impregnating the same with a quaternary compound of the general formula fabric whereby to impart thereto water-repellent surface characteristics, which comprises treating the same with an aqueous solution of N-carbomethoxy-heptadecylamino-methylene pyridinium chloride at a temperature not exceeding 40 C., drying said material at a temperature not exceeding 40 C. and then heating the dried material in the absence of moisture at a temperature between and C.

5. Cellulosic material impregnated with a surface improving reagent as defined by the process and compounds of claim 1. V 6. Cellulosic textile material impregnated according to claim 3, said textile material being characterized by having water-repellent properties and a soft feel as compared to the untreated material which properties are fast to laundering.

7. A process as in claim 1, the heating being done in the further presence of a buffering. agent.'

- 8. A process as in claim 3. the impregnation being efiected from aqueous bath and the latter of the medium surrounding the fiber during the heat treatment.

ALFRED WILLIAM BALDWIN. JOHN GWYNANT EVANS. CHARLES EDWARD SALKELD. 

